Allergic diseases including pollen allergy are considered to be multifactorial diseases. These diseases involve the expression of many different genes each of which is influenced by various environmental factors. Thus, it is very difficult to identify a specific gene which causes a specific disease.
Additionally, allergic diseases are thought to involve the expression of mutated or defective genes, or overexpression or reduction of the specific gene expression. To elucidate the role of gene expression in diseases, it is necessary to understand how a gene is involved in triggering disease onset and how expression of the gene is altered by external stimulants such as drugs.
Recent developments in gene expression analysis techniques have made it possible to analyze and compare the gene expression of many clinical samples. Among these methods, the differential display (DD) method is significantly useful. The differential display method was originally developed by Liang and Pardee in 1992 (Science, 1992, 257:967–971). By using this method, one can screen several tens or more different samples at one time and it is possible to detect altered gene expression among the samples. By revealing alterations in gene expression due to mutation as well as time- and environment-dependent gene expression, it is expected to provide important information about disease-related genes. Such genes include those of which expression is influenced by environmental factors.
Among allergic diseases, pollen allergy has recently become more common. It is considered that some genes whose expression is affected by pollen, one of the environmental factors, are involved in cause of pollen allergy. Based on this situation, it was hoped that genes involved in pollen allergy could be isolated.